Quaternary compounds having anti-microbial activity

ABSTRACT

Anti-microbial quaternary ammonium compounds which include the adamantane ring system linked to the quaternary ammonium group by a hydrocarbon chain or by other functional groups, such as ether, carboxylic ester, carboxamide, keto, carbamate ester, thiocarbamate ester, etc.

This is a divisional of application Ser. No. 606,138, filed Aug. 20,1975, now abandoned, which was a division of Ser. No. 400,097, filedSept. 24, 1973, now U.S. Pat. No. 3,928,411, issued Dec. 23, 1975, whichis a continuation of Ser. No. 39,536, filed May 21, 1970, now abandoned.

The present invention relates to novel quaternary ammonium compoundsrepresented by the general formula:

    [RZ (CH.sub.2).sub.n N.sup.+ (CH.sub.3).sub.2 R.sup.1 ] X.sup.-

wherein R is 1-adamantyl (C₁₀ H₁₅), R¹ is a long chain alkyl group of10 - 18 carbon atoms, Z is selected from the group consisting of [CH₂,O, S, C═O, COO, CONH, CHOH, NHCOO, and NHCSO.], n is an integer from 1to 3 and X is a compatible anion. These quaternary compounds possesssuperior anti-microbial, anti-caries and anti-calculus activity.

The adamantyl radical is derived from tricyclo-[3.3.1.1³,7] decaneshowing four trans cyclohexane rings as follows: ##STR1##

Typical examples of the quaternary ammonium compounds which may be usedin this invention are:

2-(1'-adamantanecarbonyloxy)ethyldimethyldecyclammoniumbromide,

2-(1'-adamantanecarbonyloxy)ethyldimethyltetradecylammonium bromide,

3-(1'-adamantanecarboxamido)propyldimethyldodecylammonium bromide,

3-(1'adamantanecarboxamido)propyldimethyltetradecylammonium bromide,

1-adamantyloxyethyldimethyltetradecylammonium bromide

1-adamantyloxyethyldimethyldodecylammonium bromide

1-adamantylcarbonylmethyldimethyltetradecylammonium bromide

1-adamantylcarbonylmethyldimethyldodecylammonium bromide

2-(1'- adamantylthiocarbamyloxy)ethldimethyldodecylammoniumadamantylthiocarbamyloxy)ethyldimethyldodecylammonium

The halides such as the chlorides, fluorides and analogous compounds mayalso be employed herein as effective anti-bacterials.

IT HAS BEEN OBSERVED THAT THE COMPOUNDS GENERALLY DESCRIBED BY THEFOREGOING FORMULA ARE PARTICULARLY EFFECTIVE AGAINST GRAM POSITIVEORGANISMS SUCH AS Staphylococcus aureus, Streptococcus mitis, Bacillussubtilis, Corynebacterium acnes, and against fungi, such as Candidaalbicans, Trichophyton mentogrophytes and Aspergillus niger, andmoderately effective against Escerichia coli which is a gram negativebacteria. Compounds wherein R¹ is a benzyl radical in lieu of instanthigher alkyl radical are devoid of antibacterial activity.

The anti-microbial nature of the instant novel compounds was shown by astandard test tube serial dilution test in which an appropriate numberof test tubes of broth containing decreasing concentrations of the testagent was inoculated with the test organism. After a suitable period ofincubation the tubes were examined for the presence or absence ofgrowth. The activity of the test agent was the lowest concentrationwhich inhibited the growth of the organism and is expressed as theminimal inhibitory concentration in μg/ml.

                                      TABLE I                                     __________________________________________________________________________    Minimum Inhibitory Concentration (ug/ml)                                      R     Z    R'  n S. aureus                                                                          S.mitis                                                                            B.subtilis                                                                          C.acnes                                                                             C.albicans                                                                          T.mentagrophytes                                                                       A.niger                                                                            E.coli             __________________________________________________________________________    Adamantyl                                                                           COO  C.sub.10 H.sub.21                                                                 2 1.56 6.25 1.56  1.56  12.5  7.8      31.2 25                 Adamantyl                                                                           COO  C.sub.12 H.sub.25                                                                 2 .02  .19  .19   6.25  .78   6.25     50   12.5               Adamantyl                                                                           COO  C.sub.14 H.sub.29                                                                 2 .78  .78  .1    25.   6.25  25       50   50                 Adamantyl                                                                           CONH C.sub.12 H.sub.25                                                                 3 .78  .39  --    --    6.25  12.5     25   50                 Adamantyl                                                                           CONH C.sub.14 H.sub.29                                                                 3 .39  .39  --    --    6.25  25       50   25                 Adamantyl                                                                           O    C.sub.12 H.sub.25                                                                 2 .39  .19  --    --    1.56  3.12     50   12.5               Adamantyl                                                                           O    C.sub.14 H.sub.29                                                                 2 .78  .39  --    --    1.56  6.25     50   12.5               Adamantyl                                                                           NHCSO                                                                              C.sub.12 H.sub.25                                                                 2 1.56 .78  .39   12.5  6.25  3.9      62.5 25                 __________________________________________________________________________

These dilution tests evidence the effectiveness of compounds of theinvention against bacteria and fungi.

When used against bacteria or fungi, compounds of the instant inventionmay be applied directly to the surface to be protected or may bedissolved in a pharmaceutical carrier. Typically, an effective amount,e.g. 0.1 to about 10% by weight of the compound, is included in an inertcarrier and a dispersing or surface active agent. Alternatively, aneffective amount, e.g. 0.1 to about 10% by weight may be incorporatedinto a solid carrier which may be inert, such as talc, clay,diatomaceous earth, flour, etc.

The quaternary ammonium amides of adamantyl carboxylic acid areparticularly effective in inhibiting the development of dental calculusas shown by the results of tests on litter-mated albino rats, in groupsof 15 males and 15 females who were fed a Zipkin-McClure calculusproducing diet. For 6 weeks the teeth of each animal were swabbed for 30seconds each day with a test solution or water for the control group.The animals were then sacrificed, defleshed and scored by Baer's methodfor calculus. The results were analyzed by Student's "t" test and in theresults quoted were 99% significant.

    ______________________________________                                                    Concentration                                                                            Calculus Reduction %                                   Compound      Test Solution                                                                              Males    Females                                   ______________________________________                                        3-(1'-adamantane-                                                                           .1%          43.43    6.27                                       carboxamido)                                                                  propyl tetradecyl                                                             dimethyl ammonium                                                             bromide                                                                      ______________________________________                                    

The results set forth above indicate the significant effectiveness ofthe quaternary compounds of the invention in inhibiting formation oforal calculus in concentrations as low as 0.1%.

When compounds of the instant invention are intended for use incompositions which reduce formation of caries and inhibit formation oforal calculus, they are typically incorpoated in oral preparation ineffective amounts up to about 5% by weight, preferably 0.1-1% and mostpreferably 0.25-0.5% by weight of the oral preparation. Typically, theoral preparation is a dentrifrice, such as a dental cream, tablet orpowder, containing as a vehicle about 20-95% by weight of awater-insoluble polishing material, preferably including water-insolublephosphate such as dicalcium phosphate, tricalcium phosphate,trimagnesium phosphate. The dentrifrice may also include water; binderssuch as glycerine, sorbitol, propylene glycol, and polyethylene glycol400; detergents; gelling agents such as Irish moss and sodiumcarboxymethyl cellulose; additional antibacterial agents; coloring orwhitening agents; preservatives; silicones; chlorophyll compounds;additional ammoniated materials; flavoring or sweetening materials; andcompounds which provide fluorine-containing ion such as sodium fluoride,stannous fluoride and sodium monofluorophosphate.

The oral preparation may also be a liquid such as mouth rinse whichtypically contains 20-99% by weight of an aqueous alcohol such asethanol, n-propyl, or isopropyl alcohol and being present in amount ofabout 5-30% by weight of the oral preparation.

Such oral preparations are typically applied by brushing the teeth orrinsing the oral cavity for 30-90 seconds at least once daily. Typicaloral preparations of the invention which can be applied in this mannerare set forth below.

EXAMPLE 1

    ______________________________________                                        Dental-Cream                                                                                          %                                                     ______________________________________                                        Quaternary ammonium ester                                                     of adamantyl carboxylic acid                                                                            0.50                                                Nonionic detergent*       1.00                                                Glycerine                 22.00                                               Sodium pyrophosphate      0.25                                                Carboxymethyl cellulose   0.85                                                Sodium saccharin          0.20                                                Sodium benzoate           0.50                                                Calcium carbonate (precipitated)                                                                        5.00                                                Dicalcium phosphate dihydrate                                                                           46.75                                               Flavor                    0.80                                                Water                     22.15                                               ______________________________________                                         *Tween 80 - Polyoxyethylene (20 moles ethylene oxide) sorbitan monooleate                                                                              

EXAMPLE 2

    ______________________________________                                        Mouthwash                                                                                              %                                                    ______________________________________                                        Quaternary ammonium amide                                                     of adamantyl carboxylic acid                                                                             0.25                                               Nonionic detergent (Pluronic F-68)*                                                                      1.00                                               Ethyl alcohol (containing flavor)                                                                        15.00                                              Glycerine                  10.00                                              Saccharin                  0.02                                               Water                      73.75                                              ______________________________________                                         *Block polymer of 80% polyoxyethylene and 20% polyoxypropylene           

The quaternary ammonium esters of adamantane carboxylic acid can beprepared by a two-step process of reacting adamantanecarboxylic acidchloride with a dimethylaminoethanol to form the carboxylate, followedby quaternizing with an alkyl halide as illustrated by the followingequations: ##STR2##

The quaternary ammonium amides of adamantanecarboxylic acid can also beprepared by a two-step method of reacting the adamantanecarboxylic acidchloride with a dimethyl diamine and subsequently quaternizing with analkyl halide.

Similarly, the quaternary ammonium compounds of this invention,represented by the following formulae:

    [RO(CH.sub.2).sub.n N.sup.+ (CH.sub.3).sub.2 R']X.sup.-

    [rco(ch.sub.2).sub.n N.sup.+ (CH.sub.3).sub.2 R']X.sup.-

    [rnhcso(ch.sub.2).sub.n N.sup.+ (CH.sub.3).sub.2 R']X.sup.-

    [rs(ch.sub.2).sub.n N.sup.+(CH.sub.3).sub.2 R']X.sup.-

    [rnhcoo(ch.sub.2).sub.n N.sup.+ (CH.sub.3).sub.2 R']X.sup.-

    [rchoh(ch.sub.2).sub.n N.sup.+ (CH.sub.3).sub.2 R']X

    [rch.sub.2 (ch.sub.2).sub.n N.sup.30 (CH.sub.3).sub.2 R'']X.sup.-,

wherein R, R', n and X have the same designations as in the generalformula, can also be prepared by a similar two-step method of reacting acompound containing the adamantane radical with a compound containingthe dimethyl amine radical and then quaternizing with a higher aliphatichalide.

The following examples illustrate the manner in which compounds of thisinvention are prepared.

EXAMPLE 3 Preparation of2-(1'-adamantanecarbonyloxy)ethyldimethyldodecylammonium bromide

A solution of 21.7g (0.11 mole) 1-adamantanecarboxylic acid chloride in100 ml. ether was added to a solution of 19.4g. (0.22 mole)2-dimethylaminoethanol in 200 ml. ether. The reaction mixture wasstirred overnight at room temperature. Since unreacted acid chloridecould still be detected by infrared spectrum, additional 15g. (0.17mole) 2-dimethylaminoethanol was added and the reaction mixture againstirred overnight. The reaction mixture was poured into 300 ml. waterand treated with 20 ml. of 10% NaOH solution. From the ether layer wasrecovered 23g. of oil with an infrared spectrum compatible with theproposed structure of 2-Dimethylaminoethyl 1-adamantanecarboxylate.

Analysis: Calculated for C₁₅ H₂₅ NO₂ : C, 71.67; H, 10.02. Found: C,71.26, H, 9.94.

Ten grams (0.04 mole) of the product of step 1 was mixed with 10g. (0.04mole) 1-bromododecane and allowed to stand for 6 weeks. The resultantcrystalline mass was washed with ether and dried to 17.5g. whitecrystals (88% of theory). Two recrystallizations from ethyl acetate gave15.6g. white crystals having a melting point of 176°-178° C.

    ______________________________________                                        Analysis:          Found     Calculated                                       ______________________________________                                                 Carbon    64.95     64.78                                                     Hydrogen  10.15     10.07                                            ______________________________________                                    

EXAMPLE 4

The decyl homolog of the above carboxylate, i.e., where R' is C₁₀ H₂₁,was prepared similarly to Example 3. The recovered crystals had amelting point of 183°-184.5° C and the following analysis:

    ______________________________________                                                     Found     Calculated                                             ______________________________________                                        Carbon         63.00       63.54                                              Hydrogen        9.90        9.81                                              ______________________________________                                    

EXAMPLE 5

The tetradecyl homolog was prepared in accordance with the processdefined in Example 3, yielding crystals having a melting point of 176° -178° C with the following analysis:

    ______________________________________                                                     Found     Calculated                                             ______________________________________                                        Carbon         65.33       65.89                                              Hydrogen       10.18       10.30                                              ______________________________________                                    

EXAMPLE 6

Preparation of 3-(1'-adamantanecarboxamido)propyldodecyldimethylammoniumbromide: 2.5 grams of N,N-dimethyl-1,3-propane diamine was added to acold solution of 5 grams 1-adamantane carboxylic acid chloride in 15ccbenzene. An immediate precipitate formed. The mixture was stirred andpermitted to sit for 30 minutes. The precipitate was washed with benzeneseveral times, centrifuged, and dried in vacuum, yielding 5 grams ofN-(3-dimethylaminopropyl) adamantane 1-carboxamide hydrochloride havinga melting point of 154°-157° C. This product was dissolved in 150ccacetone, placed in a refrigerator for crystal growth and 4.8 gms of theproduct was recovered.

This hydrochloride was dissolved in 100cc water and 25cc of 1N NaCH wasadded. A white precipitate formed which was extracted with ether, driedby flash evaporation and 3.2 grams of the free base having a meltingpoint of 78° -80° C was recovered. The infrared spectrum confirmed thestructure of this product.

The aforedefined reaction product was quaternized by reacting 1.6 grams(.06 mole) of N-(3-dimethylaminopropyl) -1-adamantanecarboxamide with1.5 grams (.06 mole) of 1-bromododecane dissolved in 4cc acetone. Afterstanding for 2 weeks the reaction mixture was chilled with dry ice. Theresultant crystalline mass was washed with ether, dried in vacuum andrecrystallized from ethyl acetate, giving a crystalline product having amelting point of 122°-124° C and the following analysis:

    ______________________________________                                                         Found   Calculated                                           ______________________________________                                        Carbon             64.81     65.47                                            Hydrogen           10.84     10.40                                            Molecular weight: 513.66                                                      ______________________________________                                    

EXAMPLE 7

The tetradecyl homolog of the above carboxyamide was prepared inaccordance with the process of Example 6. The recovered crystals had amelting point of 120°-122° C and the following analysis:

    ______________________________________                                                         Found   Calculated                                           ______________________________________                                        Carbon             65.80     66.52                                            Hydrogen           10.54     10.61                                            Molecular weight 541.71                                                       ______________________________________                                    

EXAMPLE 8 Preparation of 1-adamantyloxyethyldimethyltetradecylammoniumbromide

A mixture of 3.6g (0.015 mole) 1-(2'-dimethylaminoethoxy) adamantane[prepared by the method of Charkrabarti, Faulis and Szinai, TetrahedronLetters, No. 60, 6249 (1968)] and 4.3g (0.05 mole) 1-bromotetradecanewas prepared and allowed to stand at room temperature for 6 days. Theresultant solid was recrystallized from 30cc ethyl acetate to 4.75gwhite crystals. After recrystallization it melted at 132°-135°.

    ______________________________________                                                     Found     Calculated                                             ______________________________________                                        Carbon         67.32       67.17                                              Hydrogen       10.96       10.87                                              Bromine        15.92       15.96                                              ______________________________________                                    

EXAMPLE 9

The dodecyl homolog was prepared by the procedure of Example 8, yieldinghygroscopic crystals having a melting point when dry of 128°-130° andthe following analysis:

    ______________________________________                                                     Found     Calculated                                             ______________________________________                                        Bromine        16.91       16.91                                              ______________________________________                                    

EXAMPLE 10 Preparation of1-adamantylcarbonylmethyldimethyltetradecylammonium bromide

A mixture of 1.3g. (0.005 mole) 1-adamantyl bromomethyl ketone and 1.23g(0.005 mole) dimethyltetradecylamine was solubilized by the addition of30cc acetone. The next day the solidified mixture was washed with etherand recrystallized from ethyl acetate to yield 2.1g white crystals, m.p.134°-135.5°.

    ______________________________________                                                     Found     Calculated                                             ______________________________________                                        Carbon         67.72       67.45                                              Hydrogen       10.65       10.51                                              ______________________________________                                    

EXAMPLE 11

The dodecyl homolog was prepared by the procedure of Example 10 yieldingwhite crystals of melting point 140°-141.5° and with the followinganalysis.

    ______________________________________                                                     Found     Calculated                                             ______________________________________                                        Carbon         66.55       66.36                                              Hydrogen        9.87       10.28                                              ______________________________________                                    

EXAMPLE 12

2-(1'-adamantylthiocarbamyloxy)ethyldimethyldodecylammonium bromide wasprepared by a two-step process. First, 1-adamantyl isothiocyanate wasreacted with the sodium derivative of 2-dimethylaminoethanol. Theproduct after recrystallization from ethylacetate and from hexane had amelting point of 86°-88.5° and an analysis of

    ______________________________________                                                     Found     Calculated                                             ______________________________________                                        Carbon         64.02       63.79                                              Hydrogen        9.41        9.28                                              ______________________________________                                    

A solution of 4.5g of the above-prepared 0-(2-dimethylaminoethyl1-adamantylthiocarbamate and 4.0g 1-bromododecane in 15cc acetone wasallowed to stand for 4 days. The product was recrystallized fromethylacetate and from acetone in white crystals, m.p. 143°-143.5° andhad the following analysis

    ______________________________________                                                     Found     Calculated                                             ______________________________________                                        Carbon         61.04       60.99                                              Hydrogen        9.65        9.67                                              ______________________________________                                    

Although this invention has been described with reference to specificexamples, it will be apparent to one skilled in the art that variousmodifications may be made thereto which fall within its scope.

What is claimed is:
 1. anti anti-microbial pharmaceutical compositioncomprising about 0.1-10% by weight of a chemical compound having thestructural formula

    [RCOO(CH.sub.2).sub.n N(CH.sub.3).sub.2 R.sup.1+ ]X.sup.-

wherein R is 1-adamantyl, R¹ is a long chain alkyl group of 10 to 18carbon atoms, n is an integer from 1 to 3 and X is a compatible anion,admixed with a pharmaceutical vehicle, wherein said pharmaceuticalvehicle comprises an inert carrier and a surface active agent in whichsaid compound is dissolved or a solid inert carrier.
 2. A pharmaceuticalcompound as set forth in claim 1, wherein n is
 2. 3. A pharmaceuticalcomposition as set forth in claim 1, wherein X is a halide.
 4. Apharmaceutical preparation as set forth in claim 1 wherein said compoundis 2-(1-adamantanecarbonyloxy)ethyldimethyldodecyl ammonium bromide. 5.A pharmaceutical preparation as set forth in claim 1 wherein saidcompound is 2-(1-adamantanecarbonyloxy) ethyldimethyltetradecyl ammoniumbromide.
 6. An anti-microbial oral preparation comprising about 0.1-5%by weight of a chemical compound having the structural formula

    [RCOO(CH.sub.2).sub.n N(CH.sub.3).sub.2 R.sup.1+ ]X.sup.-

wherein R is 1-adamantyl, R¹ is a long chain alkyl group of 10 to 18carbon atoms, n is an integer from 1 to 3 as X is a compatible anion,admixed with an oral vehicle, which oral vehical comprises awater-insoluble dental polishing material or an aqueous alcohol.